1. Field of the Invention
The present invention relates to plugs, and more particularly, to a power plug with a main body safety feature.
2. Description of the Prior Art
Power plugs are one part of a two-part supply device used to transmit electrical power from a source wire to an electrically powered device. Instead of hardwiring the electrically powered device to the source wire, use of the jack device allows any electrically powered device comprising a power plug to be used anywhere there is a corresponding power outlet, barring a rare exception of power source incompatibility due to differing national standards.
Please refer to FIGS. 1 and 2, which show a power plug 10 and a power jack 20, according to the prior art. The power plug 10 comprises an outer casing 12, a neutral prong 14, a voltage prong 16, and a ground prong 18 set in the casing 12. The power jack 20 comprises a casing 22, and a plurality of openings 24 corresponding to the prongs 14, 16, and 18 of the power plug 10.
Being made of metal, when the prongs 14, 16, and 18 of the power plug 10 make connection with internal circuitry (not shown) of the power jack 20, electricity is conducted through the voltage prong 16 to power a device connected to the power plug 10. However, for appropriately long prongs, and appropriately small fingers, a gap left momentarily open, as the plug 10 is inserted into to the jack 20, can pose danger to a user of the supply. If the user were to accidentally use their fingers to close a circuit across the voltage prong 16 and either, or both of, the ground prong 18 and the neutral prong 14, a potentially fatal current could flow through the body of the user.
It is therefore an object of the present invention to provide a power plug with a safety measure in the form of a body that encloses prongs of the power plug.
Briefly, a power plug according to the claimed invention comprises an outer casing, a main body elastically installed on the casing, and a voltage prong and a neutral prong fixed inside the outer casing. The main body encircles the voltage prong and the neutral prong, such that when plugging in the power plug, the main body retracts to reveal the prongs, and when unplugging the power plug, the main body is pushed out to encircle the prongs.
It is an advantage of the claimed invention power plug that current carrying prongs are not left exposed, but instead are effectively covered both as the plug is plugged in, and as the plug is unplugged.